鄂尔多斯矿区冲击地压致灾机制及动力显现防治

    Disaster mechanism and dynamic manifestation control of rock burst in the Ordos Mining Area

    • 摘要: 我国煤炭开采布局逐渐向西部优化,开采深度不断向深部延伸,冲击地压灾害日趋严重。为实现鄂尔多斯矿区冲击地压有效防治,首要任务是厘清其冲击地压致灾主控因素。在鄂尔多斯矿区28座埋深超400 m的煤矿调研基础上,归纳了鄂尔多斯矿区导致冲击地压发生的主控因素:4类地质主控因素为开采深度、煤层厚度、煤岩冲击倾向性、顶板岩层结构,2类工程主控因素为煤柱留设和回采速度,并对各主控因素影响冲击地压发生的力学机制进行了分析。在地质主控因素方面,开采深度增大导致煤岩应力增大;煤层厚度与冲击地压发生可能性呈现正相关关系;煤岩冲击倾向性是衡量冲击显现过程煤岩自身能量积聚与释放能力的内在因素;坚硬厚悬顶结构会导致超前应力集中程度增大,顶板断裂释放大量动能形成动载作用于巷道围岩诱发冲击地压。在工程主控因素方面,煤柱留设宽度不合理产生应力集中与能量积聚是造成回采巷道冲击的重要因素;开采速度过大造成悬顶长度增加与应力集中程度增大,导致顶板断裂时释放更多动能。在此基础上,对红庆河煤矿、门克庆煤矿、纳林河煤矿及石拉乌素煤矿开采期间动力显现进行对比分析,并提出了冲击地压区域与局部协同防治思路与建议。

       

      Abstract: The layout of coal mining in our country is gradually being optimized towards the western regions, the mining depth is constantly extending deeper, and the hazards of rock burst are becoming increasingly severe. To achieve effective prevention and control of rock bursts in Ordos Mining Area, the primary task is to clarify the main controlling factors causing these rock bursts. Based on the investigation of 28 coal mines in Ordos Mining Area with burial depth of over 400 meters, four geological controlling factors causing rock bursts have been summarized: mining depth, coal seam thickness, coal-rock burst tendency, and roof rock structure, along with two engineering controlling factors: coal pillar design and extraction speed. The mechanical mechanisms of each main controlling factor influencing the occurrence of rock burst were analyzed. In terms of the main geological control factors, the increase in mining depth leads to an increase in coal and rock stress, and the thickness of coal seams shows a positive correlation with the possibility of rock burst. The burst tendency of coal and rock is an inherent factor measuring the ability of coal and rock to accumulate and release energy during burst events. A hard and thick suspended roof structure can lead to increased pre-stress concentration, and when the roof breaks, it releases a large amount of kinetic energy, forming dynamic loads that act on the surrounding rock of tunnels, inducing rock bursts. In terms of the main control factors of the project, unreasonable width of coal pillars leads to stress concentration and energy accumulation which are significant factors causing rock bursts in retreating tunnels. Excessive extraction speed increases the length of suspended roofs and the degree of stress concentration, resulting in more kinetic energy being released when the roof breaks. Based on these findings, a comparative analysis of dynamic events during the mining operations of Hongqinghe Coal Mine, Menkeqing Coal Mine, Nalinhe Coal Mine, and Shilawusu Coal Mine was conducted. Recommendations for coordinated regional and local prevention and control strategies for rock bursts are proposed.

       

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